Quarterdeck Office Systems, later Quarterdeck Corporation, was an American computer software company. It was incorporated in 1982. Their offices were initially located in Santa Monica, California and later in Marina Del Rey, California. In the 1990s they had a European office in Dublin, Ireland. Their most famous products were the QEMM, DESQview, CleanSweep and Quarterdeck Mosaic web browser.

In 1998, after the market for DOS utilities collapsed, Quarterdeck were acquired by Symantec (the Norton Utilities company). Symantec discontinued support of certain Quarterdeck products (eg. Mosaic), or integrated them into larger offerings (eg. CleanSweep became part of Norton SystemWorks).

=External links=